Abstract: With the rapid development of China's economy, the demand for energy, especially power supply, has increased significantly. Safe, green and reliable power supply is of great significance in promoting social and economic development. Whether the cost management level of power grid infrastructure project investment can be improved, whether the project cost is reasonable, whether the cost control is effective, and whether the investment benefit can be improved are of great significance to the construction of power grid infrastructure project. Taking the power grid project as the research object, this paper studies the problems existing in the cost control. The cost management of power grid project is divided into four stages and introduced respectively. According to the reality of power grid project cost management in power grid enterprises, this paper puts forward countermeasures and suggestions, and optimizes the process control of the project.